The Old State House is a historic building in Boston, Massachusetts, built in 1713. It was the seat of the Massachusetts General Court until 1798. It is located at the intersection of Washington and State Streets and is one of the oldest public buildings in the United States. It is one of the landmarks on Boston's Freedom Trail and is the oldest surviving public building in Boston. It now serves as a history museum that was operated by the Bostonian Society through 2019.